Patent GB-518924-A (GB)
Abstract: 518,924. Calculating-apparatus. KIEL, K. B. W. Aug. 15, 1938, No. 24072. [Class 106 (i)] An adding machine of the kind provided with a movable pin carriage, an adding mechanism, and means for reversing the adding mechanism in order to subtract, has a multplier setting means which co-operates with the adding mechanism and is adapted to operate means which controls reversal of the adding mechanism for effecting multiplication of digits above 5 by shortened multplication. The invention is described as applied to an "Astra" machine. Specification 320610, [Class 106 (i)], being referred to. The multiplier setting mechanism mounted on a base plate 103, is attached at the side of the adding machine and controls the number of cycles of the latter. The multiplier keys are conveniently divided into two rows, multplication by digits 5 and over being performed by the shortened method. The multiplicand is set up in the normal adding keyboard 301<SP>1</SP>, Fig. 3, setting pins 333, slidably mounted in a movable carriage 305, being moved into the path of abutments 332 on type bars 330 associated with racks 443. The key levers 423 engage a cross-bar 426 on an arm 427 to which is linked by member 429, a spring-urged escapement device 432, Figs. 3 and 5, comprising a toothed plate 433 having a spring-urged toothed plate 434 slidably mounted thereon, and normally in engagement with a ratchet 310 on the carriage 305. Depression of a key rocks the escapement and moves the plate 433 into, and the plate 434 out of engagement with the ratchet ; whereupon the plate 434 is moved one tooth-space by the spring 439 so that, upon re-engagement, the carriage moves one step. After the repeat key " R " has been actuated the key corresponding with the lowest denomination of the multiplier is set up in the multiplier keyboard. Taking as the first example a multiplier digit less than the value 5, the lower end of the key stem 98 engages a bar 122, Fig. 1, forming part of a link parallelogram arrangement, and this bar engages a pin 141 on a lever 142 which lever has pivoted thereto a pawl 147 engaging a similar pawl 113 pivoted to the base plate 103. This latter pawl on being pulled downward releases a spring-urged tube 107 of square-section having apertures 118 therein, the edges of which are engaged by cross pieces 106, Fig. 14, on the key stem. A rack 119, fixed to the tube 107, rotates a ratchet wheel 121, and a pin 110 on the tube which engages a lateral projection 164 on a lever 160, releases the latter so that a shoulder 282 thereon engages over the pin 141 on the depressed lever 142. Upon release of the key, the bar 122, together with the lever 142, moves upwardly, and the lever 160 is lifted together with a lever 157 to which it is pivoted. The lever 157 releases a spring-urged plate 152, one arm of which moves a bar 168 longitudinally and rocks a plate 372 about its pivot 373, which plate, by means of a projection 374 engaging a pin 375, actuates the motor key 311. The movement of the motor key is transmitted by linkage 314, 317, 318 to rock a lever 468, Fig. 2, one end 417 of which closes the circuit of the motor 473 to drive through worm gearing 475, 476, Fig. 1, a vertical shaft 479, while the other end 487 is suitably shaped to engage and restrain a pawl 481 pivotally mounted on a snail cam 484, and when the pawl is released the hooked nose 482 engages with a projection 480 on the shaft 479 so that the snail 484 is rotated and, engaging a roll 488, rocks a lever 489 which is linked to an arm 322, Figs. 2 and 3, on a shaft 323. Another arm 324 on the shaft 323 is linked to a plate 328 journalled on a shaft 329, an arm on this plate controlling through a pin-and-slot connection 350, 351, Fig. 1, the printing hammers 345. The shaft 329 carries, also, an arm 463 to which is pivoted a shouldered member 356, Fig. 3, which is moved longitudinally and engages one of the pins 354, 355, in this case, pin 355, on a rocking member 353. This latter is linked by members 461, 459 to a triangular plate 450 which, together with a second triangular plate 451, carries the positive and negative totalizor wheels 448, 456 respectively, and, therefore, determines which of the latter shall be engaged with the racks 443. During the oscillation of the shaft 329, Fig. 1, an arm 338 thereon linked by member 337 to a slide 336 carrying a cross-bar 335 engaging projections 334 on the type bars, moves upwards to allow the latter to be set from the  protruded pins 333. Means are employed to free the totalizor wheels from the racks during the upward movement and engage them during the return. An arm 505, Fig. 4, on the shaft 329 carries a spring-controlled, shouldered member 503 pivoted to it which, at the commencement of the upward'stroke, engages a pin 502 on a pivoted catch 498 to release spring - urged arms 452 pivoted to the triangular plates carrying the totalizor wheels, and so disengage the latter from the racks. On reaching the upper position, the member 503 engages a pin 511 on a lever 509 and assumes the position shown dotted. On returning, the lever 509 is pushed clockwise, and through a pin - and - slot connection 508 re - engages the totalizor wheels. The shaft 323, Fig. 6, carries an arm 400 linked to an arm 405 which engages by means of a pin 407 a depending portion 177 of a slide 174, which slide carries a pawl 180 having a lateral projection 184 which engages the ratchet wheel 121 and steps it back one tooth for each cycle of the machine. On being returned to its initial position, a pin 287 on the ratchet wheel engages a projection 290 on the plate 152 and rocks the latter so that the bar 168 is allowed to move back and the stop key is released. A pawl 214 which has been engaged with a projection 369 on a slide 365, pulls the latter to the right and rotates an arm 207 which is linked by a member 376 to an arm 378, Fig. 1, spring-connected to an arm'381 fixed to a shaft 380. Another arm 385 on this shaft engages by means of a pin 386, a depending portion 361 of the " O " adding key lever, and, therefore, causes the carriage to to be moved to the next decimal position. A bell-crank lever 392, Fig. 6, oscillates during this movement to release the slide 365 from the pawl 214, while a slide 188 engaged by a projection 186 on the slide 174, serves to restore the lever 160, Fig. 1. Since the shortened method is used for multplier digits of five and over, the machine is arranged to subtract the complement, in these cases, and cause an additional cycle in the next higher denomination. Two U-sectioned bars 227, 228, Fig. 14, are slidable inside the tube 107. These bars have apertures therein identical with those in the tube, but can be moved out of register with the latter, against the action of a spring, a distance corresponding to one toothspace of the ratchet wheel 121, Fig. 1. These alternative positions are secured by hooked members 234, 237 pivoted on bars 227, 228 respectively, and engaging recesses in the tube 107. They are controlled by abutments 241, 242 on slides 243, 244, Figs. 1 and 16, which are pivotally connected to a common lever 248, and are engaged at their slotted lower ends by arms 258, 260 pivoted at 132 and fixed to arms 130, 135 controlled from the two parallelogram bars 122, 123 through links 127, 128 and pin - and - slot connections. When the slide 243, Fig. 16, is moved to its lower position, a pin 250 thereon, engaging a recess in a plate 408, pulls the latter downward so that a lever 410 to which it is pivoted is rotated and lifts an arm 416, Figs. 16 and 1, together with an extension 418 which lifts the shouldered setting plate 356 into its upper position to engage the upper pin 354 and set the totalizor for subtraction. The plate 408 can also be moved over to the right, Fig. 16, by means of a handle 420<SP>1</SP>. The bars 122, 123, Figs. 13 and 14, are bent away to avoid the slides 98 of the " 0 " and " 9 " keys which, in cases where no adding or subtracting is necessary. engage levers 263, 264 pivoted on a plate 266 itself pivoted on a second, slidably - mounted plate 268 which engages an arm 279 and rocks an arm 207 linked by member 376, Fig. 1, to the arm 378 and so operates the shifting mechanism. When an operation of the machine is necessary, on depression of the " 0 " or " 9 " key, a projecting tongue 294 on the upper portion of one of two levers 293 pivoted on extensions fixed to the bars 122, 123 is positioned in the path of the key slide 98. The lower ends of the lever 293 are linked to the bell-cranks 258, 260.